1. Field of the Invention
This invention relates to a three-dimensional structure of concentric rings, in particular a container of plastic material.
2. Description of Prior Art
Such known containers are relatively rigid. When not in use, they require a relatively large amount of space, unless several of such containers can be placed one inside the other, which is not always possible. This disadvantage has been recognized and a collapsible cup of aluminum or plastic, constructed of a plurality of ring elements, has been assigned for tourists. Such conventional cup can be pushed together to the height of these rings and therefore require less space in the backpack for example. However, it has one great disadvantage of not being absolutely fluid tight, it leaks when put down or even collapses, so that the contents are lost.